Plasmonic laser comprising: a metal nanostructure (RP) supporting a plurality of plasmon modes; and a gain medium (MG), providing optical gain at the frequency of oscillation of at least one of said plasmon modes, coupled in the optical near field with said nanostructure, characterized in that said gain medium is structured at the nanoscale so as to have a shape that closely follows the spatial intensity distribution of one of said plasmon modes, at the frequency at which said gain medium has an optical gain. Process for fabricating such a plasmonic laser.

The invention relates to novel triphenylamine derivatives for use as fluorophores, in particular for two-photon microscopy in biology. It also relates to compositions containing these derivatives, to the use of these compositions and also the derivatives themselves for labelling biological molecules (or 'biomolecules') such as nucleic acids, oligonucleotides, proteins, polypeptides, plasmids, etc., with a view to observing them in particular by two-photon microscopy, and to biomolecules labelled with said derivatives. Applications: biological and medical imaging (fundamental research for the structural or functional study of biological systems, applied research for clinical or therapeutic purposes, diagnosis and medical screening, etc.).